Mechanical hand for artificial arms



` E. C. JARRETT MECHANICAL HAND FOR ARTIFICIAL ARMS May l2, 1944.

Filed March so, 1943 INVENTOR.

Ed d e C. Jaffe# JIT To //Vfy.

Patented May 2, 1944 UNITED STATES PATENT DFFICE MECHANICAL HAND Fon ARTIFICIAL ARMs Eddie Craig Jarrett, Fillmore, Calif.

Application March 30, 1943, Serial No. 481,167

(Cl.` .3f- 112) Claims.

My invention relates to a mechanical hand for anV artificial arm of `which there are a variety of such implements heretofore used and known. My invention being an improvement for better service and use than any other' appliances or mechanisms heretofore used or known by me.

My mechanical hand is operated by the wearer in the same manner as are other mechanisms ofv this type. by having a cord or suitable cable extending from the hand up the sleeve of the natural arm and over and around the shoulder blades whereby on shrugging or moving the shoulders a tension is produced cn the cable whichl opens the fingers of the mechanical hand, While a spring mechanisml in the hand itself makes' the closure of the n'gers.

My mechanicaly hand is applied to the stump of the natural arm in a similar manner as are other similar deviceby being held rotatively in the end of a suitable sleeve of leather or other material which is laced and secured in any suitablemanner to the stump end of the arm remaining of natural character.

My invention relates' to' details of constructions whch add to theeniciency and convenience in theuse of a mechanical hand'.

An objectv of" my' invention is to provide a simple and' inexpensive construction which canbe made at small? expensev and yet` arrive at efciency of service not heretofore obtained by other devices or appliances known.

A further object of the invention is to provide shapes of theV ngers for amechanical hand- Which will holdv with more security and aiiord more general service and convenience in* the use of this handthan has heretofore been accom plished, insofar as I have beeny informed.

Other objects of the invention will appear by the descriptions and the claims hereof.

Reference will be had to the accompanying drawing in which:

Fig.V 1 isa perspective' view of my mechanical hand mounted in the end; of thev holding sleeve which is mountedon'tlie front end'v of the stump of a= natural arm.

Fig. zisa top plan* viewfof my invention.

Fig. 3 is:y a side@ elevationof 4` what is' shown i'n Fig. 1! withA parts brokenY away for inspection and for clear'ness'of illustration.

Fig. 4 isa sectionon line 4&4" of Fig. 3;'

Fig. 5v is a perspectiveY View' of. detailed' parts lookinginA the direction' of an arrow small a of Fig. 3'. i

Fig. G is a perspective view of parts shown at the right of Figs. 2 and 3K.

In the drawing 2LA indicates the mechanical sleeve which isl attached in any suitable manner to the' stump end of a natural arm.V In the outer end of this sleeve there' is a circular socket, not indicated in the drawing as it is of common general construction and isv not generally shown herein. My invention is secured to this socket like' other mechanical handsv by' means of a.' circular disk 3 of any suitable form. The point being that this mounting in the sleevel 2 providesv that the disk 3 may be rotated therein in the end of said sleeve 2d through any suitable arc desired for service ofa mechanical hand'.

The actions kproduced by the wearer are brought about by an operating cordI or cable 4 which extends up the sleeve of thel wearer and up andi around the shoulders of the wearer in the same manner as is common practice with other devices of this character whereby the movements of the shoulders produce a tension on the operating cord 44 which results in opening the finger bars 5 of the mechanical hand through the mechanism hereinafter described", tensionof the cable or cord l pulls the tube 8 to the right, the tube 8 in turn putsl tension on the tie rods 2U', thereby causing the'flngers 5 to' open, see Figs. 2-Y and' 3; and o'n the releasev of the tension of the' cord', spring. means ill in the mechanical handv close the' ngers of the handon to any object which may be grasped by the' mechanicalV hand.

My invention is' provided with n'g'e'rsbarsT 5 which are hinged by pins 6 to a circular supporting longitudinal bar 'l which extends back abuts against theaforementon'ed circular diskf".

A spring l0 is mounted over thel longitudinal bar I and abuts against the circular disk 3f and the other end of therspring IO'abuts` againstthe end of the movablel tube 8 with an'- eztnding pressure to' push hief tube a' runder from the disk 3. oni this eiidl or` me' tri-e- 81 wnieiiabuts are screwed into perforations in the disk 3. On the other side of the plate I3 there is a projection I6 into which the operating cord or cable 4 is secured.

The movable tube 8, at the left end thereof, has mounted thereon a block I1, see Fig. 5, which is held in place by collars I8, one on each side, and which allow the block I1 to revolve on the end of the movable tube 8. This block I1 is provided with horizontal flanges I9 at right angles to the main face of the block I'I.

'Iie rods 20 have their ends turned over and seated into the flanges I9 of block Il. The tie rods have their other ends 2l hinged into apertures in the outward portions of the fingers bars 5.

Thus when the cable 4 is stressed and moved in the direction of the arrow 22,'see Fig, 2, the spring I is compressed by the movement of the plate I3 from the full line position shown in Fig. 2 to the dotted lines in said ligure. in moving the block Il to the right along the tube 8 and this movement results in opening the fingers bars 5 from the full line positions to the dotted lines, as shown in Fig. 2, thus opening the nger bars 5 which permit the entrance of anything which is desired to be grasped by the mechanical hand as and when actuated through the means of the cable 4 as earlier described herein.

The fingers bars 5 are provided with hook shaped ends 23 on which there are provided circular ynotches 24 adaptable for grasping any small articles. The hooked sh-aped ends 23 enable the mechanical hand to hook on to anything which may be desired' which may be engaged by such a hook form as is indicated in the drawing. l

Notches 25 in the vertical side of the fingers bars 5 provide means for grasping securely any small articles such as pencil 26, as is shown in Fig. 1.

In inner'edges 21 of the ngers bars 5 are milled for roughening purposes with a series of criss-cross small notches or serrations which assist in holding articles firmly.

The forms and constructions of the parts are of simple shapes and are adapted to be made with relatively few special tools and thus bring down the costs which will permit the furnishing of mechanical hands at little expense to those who most need them, for as a matter of fact, most of the persons who require articles ofthis class are in thelower earning brackets.

The mechanisms of this mechanical hand provide a greater variety of uses and are more rm in their grasp upon anything to which it is applied to with more general efficiency than any other artificialY hand ormechanical device for use as a hand. Y

The finger bars 5 are provided with parallel companion sides which contact each other substantially their entire service` length. VThis widens the service for firmly grasping varyingY shaped objects. Y

I have shown herein a round bar 'I with a flattened end as the central supporting member for the mechanisms of the hand, together with a movable member in the form of a tube sliding over the longitudinal round bar. In place of this tube I might make a companion bar ork two companion bars, not necessarily tubular, which I would mount alongside the longitudinal bar 'l for the movable member whichfunctions in the vplace ofY the tube 8, as shown in the drawing, but I prefer to use the tube.

What I claim is:

1.. In a hand of theclass described, a circular! diskl adapted to-be fitted into a supporting sleeve This results of the type which may be fastened to the stump end of a natural arm, a circular bar extending through the said disk from the outside of the said sleeve and the end of the said circular bar provided with a fastening means in the form of a nut screwed thereon and the like, a coil spring mounted on the said bar and abutting against the said circular disk the opposite end of said spring abutting against a tube which tube encloses the said circular bar, a ange nut on the end of saidtube'adjacent tothe said spring, a covering tube mounted over the said coil spring and sliding on said flange nut and extending in contact with the said disk, a plate mounted on the end of said tube adjacent to the said flange nut and adapted to be rocked in angular direction on said tube, a stirrup hinged to the said `plate at one side thereof and said stirrup secured into the aforementioned circular disk, a projection on said plate opposite the said stirrup, a cable connected to the said projection, said cable extending up and around the shoulders of the wearer of the hand whereby the hand is operated in functioning, collars fastened on to the outer end of the said tube, a flat block mounted on and between the said collars, said block having flanges turned on its body on each side thereof to a horizontal position, tie rods having their ends Aturned over and hinged in the said flanges, the said circular bar at its outer end extending outside of the said tube and having its ends attened, linger bars hinged into the said flattened end of the said circular bar, the aforementioned tie rods having their outer ends turned over and hinged into the said nger bars, said finger bars having milled serrated edges on their sides acljacent to each other and the ends of said finger bars turned over into a hooked'shape, curved notches opposite each other on the vertical inside edges of said linger bars forming an aperture adapted to hold an article such as a pencil and the like, a set of curved notches extending horizontally through the body of the said hooked over ends of the said linger bars for the purpose of holding pencils and the like.

2. In a hand of the class described, a longitudinal bar having a flattened outer end, linger bars hinged into the said flattened end of the said bar and extendingoutwardly from the said bar, a tube into which the said bar extends rearwardly, a block mounted on the outer end of said tube and adapted to be revolved thereon, horizontal flanges on the transverse sides of said block, tie rods hinged into the said flanges of said block and extending outwardly from said block, said tie rods hinged into the body portion of said linger bars; in combination with spring means for moving the said tube outwardly along the said bar which is located within the said tube together with manually operating means for moving the said tube inwardly over the said bar.

'3. In a hand of the class described, a longitudinal bar having a flattened outer end, linger bars hinged into the said flattened end of the said bar and extending outwardly from the said bar, a tube into which said bar extends rearwardly, a block mounted on the outer end of said tube and adapted to be revolved thereon,. horizontal flanges on the transverse sides of said block and .extending outwardly from said block, tieV rods hinged intosaid flanges, said tierods hinged into the body portion of said linger bars,.- ,said finger bars hinged to the said longitudinal" `-bar having their main body portions of their companion sides parallel to each other and roughened, together with Vertical notches transversely of their parallel sides, the ends of said finger bars curved over in hook form, horizontal notches in the companion sides of said hooked ends; in combination with spring means for moving the said tube outwardly along the said bar which is located within the said tube together with manually operated means for moving the said tube inwardly over the said bar.

4. In a hand of the class described, a longitudinal bar forming a supporting member for the hand, said bar xed into a disk, said disk mounted in a sleeve adapted to be xed to the stub arm of a person, a movable member mounted on and along the said longitudinal bar and adapted to slide thereon, a spring mounted on said longitudinal bar and adapted to contact the said movable member and press said member outwardly on said longitudinal bar, manually operative means connected to said movable member for withdrawing said movable member compressing said spring, finger bars hinged together on the outer end of said longitudinal bar and extending outwardly therefrom, a block mounted on the outer end of said movable member, said block provided with two horizontal anges oppositely opposed transversely of said block, tie rods hinged to the said anges of said block and extending outwardly beyond the ends of said longitudinal bar and movable member, said tie rods hinged into the body portions of said nger bars.

5. In a hand of the class described, a sleeve adapted to be attached to an arm of a person, a socket in the end of said sleeve, a disk mounted in the said socket, a longitudinal supporting bar having its inner end fixed into the said disk, a tubular movable member mounted over said longitudinal bar, a spring mounted over the inner end of said longitudinal bar, said spring abutting against said disk and with its other end abutting against the inner end of said tubular movable member and adapted to press the tubular member away from the said disk, a plate mounted on the inner end of said tubular member and adapted to engage and push said tubular member against the said spring, a stirrup xed into the said disk and extending forward and hinged to one side of said plate, a projection on the other side of said plate opposite the said stirrup, an operating cord connected to the said projection of said plate; in combination with suitable nger bars hinged to the outer end of said longitudinal bar, said finger bars extending forwardly from the end of said longitudinal bar, suitable `connecting rods hinged into said nger bars and extending rearward of said bars and suitably connected to and be moved by said tubular member.

EDDIE CRAIG JARRETT. 

